Vehicle suspension

Abstract

A vehicle suspension for motor vehicles in which a semi-active suspension is combined with an active suspension to make a novel suspension. The pump power of the active suspension, however, is designed merely for overcoming the necessary frictional forces. The advantage is that for such a vehicle suspension, a lightweight pump of low power, small diameter lines, and a small 4/3-way magnetic valve requiring little current can be used.

What is claimed and desired to be secured by Letters Patent of the United States is: 
     
       1. A vehicle suspension for motor vehicles having a shock absorber, said shock absorber comprises a semi-active suspension supplemented with an active suspension equipped with a fluid energy supply system having a pump (13, 36) and reservoir (37), a first magnetic valve for controlling fluid from said pump to said shock absorber, a second magnetic valve (31) for controlling fluid in a line parallel with said shock absorber, means for varying an electrical signal to said first and second magnetic valves, and said pump has an output power equivalent to from 50 to 100W per wheel and is dimensioned to produce an output power which is only sufficient for overcoming frictional forces in said shock absorber (28). 
     
     
       2. A vehicle suspension as defined by claim 1, which includes a 4/3-way magnetic valve (35) for controlling the shock absorber (28), said 4/3-way magnetic valve having a controllable cross section which is so small that the controlled power is sufficient merely for overcoming the frictional forces in the entire suspension. 
     
     
       3. A vehicle suspension as defined by claim 1, in which said magnetic valve includes a throttle (31) and a magnet (32) for varying the shock absorber fluid constant, and said 4/3-way magnetic valve (35) for controlling the energy supply are combined into a common valve block. 
     
     
       4. A vehicle suspension as defined by claim 2, in which said magnetic valve includes a throttle (31) and a magnet (32) for varying the shock absorber fluid constant, and said 4/3-way magnetic valve (35) for controlling the energy supply are combined into a common valve block. 
     
     
       5. A vehicle suspension for motor vehicles comprising a shock absorber, said shock absorber including upper and lower identical work chambers, separated by a piston, a 4/3way magnetic valve, first and second fluid lines connectd at one end to said upper and lower work chambers and at the opposite end to said 4/3way magnetic valve, a third fluid line connected to said first and second fluid lines between said 4/3way magnetic valve and said shock absorber in parallel with said upper and lower work chambers, a variable throttle valve in said third fluid line, a fourth fluid line connected from said 4/3way magnetic valve to a reservoir, a fifth fluid line connected from said 4/3way magnetic valve to said reservoir, a pump connected in said fifth fluid line and a reservoir connected between said pump and said 4/3way magnetic valve. 
     
     
       6. A vehicle suspension for motor vehicles as set forth in claim 5 which includes a computer which controls said variable throttle valve and said 4/3way magnetic valve whereby said variable throttle valve is closed when said 4/3way magnetic valve is activated and said variable valve is open when said 4/3way magnetic valve is not activated.